If using frozen cooked shrimp, thaw and use paper towels to press excess water from shrimp or dip will be watery.) In a medium mixing bowl, combine first 8 ingredients. Refrigerate at least 1 hour. In a small bowl, combine spinach, cream cheese and salt. Spread on tortillas and set aside. Use a slotted spoon (to avoid any excess liquid) and spoon seafood mixture over spinach on each tortilla. Roll up and place on a large baking sheet. Cover with plastic wrap; refrigerate at least 8 hours or overnight. With a serrated knife, cut each roulade into 1- to 1 1/2-inch slices. Place cut-side-down on a serving tray and sprinkle with additional green onions and Old Bay seasoning. May be prepared up to 4 hours ahead of time and covered with plastic wrap.